The people of Haiti have begun voting in the country's first elections since former President Jean-Bertrand Aristide was ousted in February 2004.

Voters are picking a new president, as well as a 129-member parliament.

The presidential front-runners are Rene Preval, a former ally of Mr Aristide, and Charles Henry Baker, a businessman.

Thousands of heavily armed UN troops are watching over the election process, which has been delayed several times because of widespread unrest.

The UN says the election offers Haiti a chance to escape chronic instability.

Polls opened at 0600 (1100 GMT) and are scheduled to close at 1600 (2100 GMT). Official results are expected on Friday.

Hours before the polls opened, queues of people waited to cast their votes in what is expected to be a high turnout.

The country has been run by an interim administration since 2004.

'Away from violence'

Some of Haiti's 3.5 million registered voters live some way from a polling station.

The roads and transport are so poor in some areas that ballot papers and boxes had to be delivered by helicopters - and in some areas by mules.

One man waiting at a polling station in the capital, Port-au-Prince, told the BBC that he had left his house in the mountains at midnight and walked for more than four hours to take part.

"I came to vote for my charismatic leader [Rene Preval] so that he can run my country," he said.

The BBC's Claire Marshall in Port-au-Prince says Haiti's poor majority believe Mr Preval is the only candidate who understands their misery.

UN Secretary General Kofi Annan sent a message to Haitians ahead of Tuesday's poll, saying: "These elections offer an opportunity for your country to move away from violence and uncertainty towards a future of peace and stability."

Despite the presence of peacekeepers, the country has continued to be blighted by political and criminal violence and instability.

Aristide loyalists

Former President Preval, 63, is a long-time ally of Mr Aristide who is popular with the poor.